Organic Light-Emitting Diode (OLED) display panels have some features, such as being self-luminous, high brightness, wide viewing angles, high contrast, being flexible, and having low power consumption. Therefore, they are widely used in mobile phone screens, computer monitors, and full color TVs. OLED display panels comprise self-emitting OLED elements, wherein organic light-emitting diodes are current-driven components. Brightness of the panels are driven by current passing through OLED components. OLED cathodes are easily affected by voltage drop (IR drop) so that the current passing through the OLED elements is reduced and affects the display brightness. When the current is greater, the brightness decreases more.
Adjusting gamma of the panel brightness collects the brightness in different colors and different grayscale voltages, then division of the corresponding grayscale is processed. The division of the grayscale having different colors is determined by IR drop of the corresponding color pixel. However, as shown in FIG. 1, a cathode layer 11 of OLED panel is a layered structure, wherein the cathode layer 11 is inputted the same cathode voltage VSS, and all pixels are connected to a common cathode so that the brightness of the pixel will be affected by the current of the panel and IR drop, and IR drop of the panels are the same. Thus, a difference is generated between actual gamma adjustment and panel brightness so that the panel has color cast.
As a result, it is necessary to provide an organic light-emitting diode display to solve the problems existing in conventional technologies, as described above.